PF-04929113 (SNX-5422)

2 years -80 in solvent

PF-04929113 is administered orally 3 times per week, total 3 weeks.

MCF-7, SW620, K562, SK-MEL-5 and A375 cancer cell lines

0-300 nM

PF-04929113, is dissolved in 1% carboxy methylcellulose/0.5% Tween 80 at 10 mg/mL and stored at 4 C for in vivo study.

PF-04929113 is a small-molecule Hsp90 inhibitor based on the 6, 7-dihydro-indazol-4-one scaffold. PF-04929113 developed by Serenex, converts to SNX-2122, which is the active Hsp90 inhibitor form. PF-04929113 exhibits potent effects on Her-2 stability and causes expected up-regulation of Hsp70. PF-04929113 shows potent antiproliferative activity against a broad range of cancer cell types, e.g. MCF-7 (IC50=16 nM), SW620 (IC50=19 nM), K562 (IC50=23 nM), SK-MEL-5 (IC50=25 nM), and A375 (IC50=51 nM). [1]

72 or 144 hours

All assays are done in 96-well plates. All cell lines are purchased from ATCC. Proliferation rates are measured by seeding cells into 96-well plates, followed by compound addition 24 h later. After addition of PF-04929113, cells are allowed to grow for either an additional 72 or 144 h depending on rate of growth. At harvest, media is removed and DNA content for individual wells is determined using CyQuant DNA dye. Levels of Hsp90 client proteins and phosphor-regulated proteins in A375 are measured by high content analysis (HCA) using an ArrayScan 4.5 instrument after 24 hours of treatment with PF-04929113, followed by methanol fixation. After fixation in 4% PBS-buffered formalin and permeablization with 0.1% TX-100, cells are probed with anti-Her2, antiphospho-S6 (pS6), antipERK, and anti-Hsp70 primary antibodies, followed by TRITC or FITC conjugated secondary antibodies. Nuclei are also stained with Hoechst DNA binding dye. For each well, 250-500 individual nuclei are identified along with the average staining intensity for the client and phospho-proteins for each cell. Average client staining intensities are then calculated for each well.

PF-04929113 (SNX-5422) is a potent and selective HSP90 inhibitor with Kd of 41 nM and induces Her-2 degradation with IC50 of 37 nM. Phase 1/2.